This invention relates to improvements in rotary lawn mowers, and, more particularly, to an attachment for rotary lawn mowers which facilitates the destruction and collection of leaves during the lawn mowing operation.
Removal of leaves from lawns presents a serious problem for home owners and gardeners who have responsibility for maintaining lawns. Most often, the leaf-raking operation is separate from the lawn cutting, and it is advantageous to combine them in one operation. Certain types of mowers reduce the leaves to a very small size and evenly distribute them on the lawn, while others are designed to entrain the leaves in moving air streams together with grass clippings, and to collect both for removal in bags, bins, or other suitable means. In order for these devices to function, it is necessary to run the mower over the leaves on the lawn. With the exception of recently developed and very expensive models that are designed to create a high vacuum, most mowers project air both into and out of the under side of the mower, with the result that passage of the mower over the lawn causes movement of leaves in a direction away from the mower. While not all leaves escape, those that do are sufficient in number to require a separate raking operation or several passes of the mower over the lawn to do a complete job.
A large number of devices are available in the prior art which are designed to improve the operation of rotary type lawn mowers. One such device is shown in U.S. Pat. No. Re. 31,930 to Luick, which describes means by which the mower can be converted to a vacuum sweeper by adding an adjustable skirt of preferably flexible material at the lower edge of the peripheral wall defining the grass-cutting chamber. While this device is suitable for cleaning dirt and debris from level areas such as sidewalks and paved driveways, it does not provide sufficient clearance to enable a moving mower to ride over and capture dry leaves which occur all too frequently on lawns in the fall of the year.
Another patent of interest is U.S. Pat. No. 3,029,533. The device of this patent provides means for modifying a rotary lawn mower so that it acts as a snow-blowing device. Modifications include provision of disc type wheels to break up snow under the mower, replacement of the grass cutting blade by a snow-blowing flinger, and the provision of a skirt on the bottom of the mower housing.
Another disclosure, that of U.S. Pat. No. 3,400,523 provides means for separately pressurizing the interior of the lawn mower housing to cause the frame to rise relative to the ground. In this case, a flexible rubber skirt is provided under the lawn mower housing to restrict the exit of air from the periphery of the motor housing thus forcing most of the air through the discharge passage to improve the collection of debris from under the mower. Sufficient air continues to escape from under the mower, however, to cause the above-described problem with leaves being pushed away from the mower.
It is also known to provide guards or shields depending either from the front or rear of a rotary type lawn mower to prevent or retard accidents caused by placing ones foot under the mower or by objects such as stones which may be flung from the mower during its operation. Patents which disclose such devices include U.S. Pat. Nos. 3,226,920, 3,727,386 and 4,241,567. None of these prior art references, however, are seen to address the problem caused by the escape of air laterally from under the mower housing which action causes movement of leaves and other debris in a direction away from the mower while the mower is moving over the lawn. This unwanted action requires substantial additional work to complete the raking and cutting of a lawn in the fall of the year.